(1) Field of the Invention
THIS INVENTION relates to a security device for trolleys or other equipment stored in queues, rows or stacks. The invention is particularly suitable for, but not limited to, a security device for supermarket trolleys.
(2) Prior Art
Large supermarkets may provide several hundred shopping trolleys for the convenience of their customers. The collection of the shopping trolleys from the surrounding car parks is very labour intensive, as there is little incentive for shoppers to return the trolleys to designated collection points.
A system has been developed in West Germany where the shopping trolleys are releasably connected together in queues and stacks within the supermarket. The customer inserts a coin into a unit which connects adjacent trolleys in each queue or stack to release the first available trolley. On returning the trolley to the trolley queue or stack, and connecting it to the queue or stack, the unit returns the coin. While this system has reduced labour costs for the collection of the trolleys, it has been found that the units can easily be tampered with, fail to release the coins, and are prone to frequent failure due to internal wear and damage.